BIOASSAY/CHEMICAL FRACTIONATION OF TOXIC CHEMICALS IN ST LAWRENCE RIVER SEDIMENT

在圣路易斯马塞纳地区的一家铝厂附近收集的沉积物。 劳伦斯河是致命的水生昆虫，摇蚊幼虫 滕坦人。 初步研究表明， 多环芳烃（PAHs）、多氯联苯（PCBs） 和多氯二苯并对二恶英/多氯二苯并呋喃 沉积物中的多氯二苯并呋喃（PCDFs）不能解释沉积物的毒性。 本提案的主要目标是确定 沉积物中的有毒化合物， 化学馏分 这种新的方法，称为生物测定定向化学 分析可以大大简化有毒化合物的鉴定， 复杂的环境样本。 这项任务将在三年内完成 阶段。 在第一阶段，将依次提取沉积物 用极性增加的两种溶剂（甲苯和甲醇）， 用水提取。 浸提液将经受一组 体内和四个体外生物测定以确定急性毒性， 遗传毒性、雌激素/抗雌激素和神经毒性。 为 急性毒性测定我们将使用摇蚊幼虫 在我们以前的工作中使用的程序，也是一个快速的细菌测定基于 有毒物质减少发光体的光输出的能力 细菌。 遗传毒性将使用非发光变体进行评估， 通过突变可以恢复发光的细菌。 雌激素性/抗雌激素性和神经毒性将通过 基于MCF-7人乳腺癌生长的哺乳动物细胞系统 细胞和脑片中的儿茶酚胺代谢。 的 选择的生物测定法简单快速，它们涵盖了一系列重要的 生物反应，可能产生不利的健康影响， 人口。 在第二阶段，提取物将进行化学处理， 分馏和不同的馏分将由 上述生物测定。 显示增加或减少的分数 相对于它们所来源的提取物的毒性将 使用最先进的仪器分析有毒化合物，如高和 低分辨率质谱仪和傅里叶变换红外光谱仪 谱 在最后阶段， 有毒化合物将通过将鱼类暴露在沉积物中来确定， 实验室

Sediment collected near an aluminum plant in the massena area of the St. Lawrence River are lethal to larvae of the aquatic insect, Chironomus tentans. Initial studies suggest that concentration of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDD)s/polychlorinated dibenzofurans (PCDFs) in the sediment cannot account for the toxicity of the sediment. The major objective of this proposal is to determine the complete range of toxic compounds in the sediment using bioassays in conjunction with chemical fraction. This novel approach, termed bioassay-directed chemical analysis can greatly simplify the identification of toxic compounds in complex environmental samples. The task will be accomplished in three phases. In the first phase the sediment will be sequentially extracted with two solvents (toluene and methanol) of increasing polarity followed by extraction with water. The extracts will be subjected to a battery of one in vivo and four in vitro bioassays to determine acute toxicity, genotoxicity estrogenicity/antiestrogenicity and neurotoxicity. For the acute toxicity measurements we will use the Chironomus tentans larvae procedure used in our previous work and also a rapid bacterial assay based ont the ability of a toxicant to reduce light output from a luminescent bacterium. Genotoxicity will be assessed with a nonluminescent variant of the bacterium to which luminescence can be restored by a mutation. Estrogenicity/antiestrogenicity ad neurotoxicity will be evaluated by mammalian cell systems based on the growth of MCF-7 human breast cancer cells and catecholamine metabolism in rat brain slices respectively. The selected bioassays are simple and rapid and they cover a range of important biological responses which could produce adverse health effects in the human population. In the second phase the extracts will be subjected to chemical fractionation and the different fractions will be evaluated by the bioassays described above. Fractions showing an increase or decrease in toxicity relative to the extract from which they were derived will be analyzed for toxic compounds using state-art-instruments such as high and low resolution mass spectrometers and Fourier Transform infrared spectroscopy. In the final phase the bioaccumulation and/or metabolism of the toxic compounds will be determined by exposing fish to the sediment in the laboratory.